1. Field of the Invention
The present invention relates to an optical fiber butting system for butting two optical fibers against each other and an optical fiber fusion-splicing system for fusion-splicing two optical fibers, and more particularly, to an optical fiber fixing system for fixing each optical fiber before butting or fusion-splicing the two optical fibers.
2. Description of the Related Art
An optical fiber fixing system for fixing an optical fiber is used for an optical fiber butting system (an optical fiber alignment system) or an optical fiber fusion-splicing system. As an optical fiber fusion-splicing system according to the related art, known is one disclosed in Japanese Patent Publication Laid-Open No. 6-258541. As shown in FIG. 1, an optical fiber fusion-splicing system 101 includes optical fiber fixing systems 105, 105, an optical fiber butting section 107, discharge electrodes 109, 109, a system main body 111, a windshield cover 113, a hinge portion 114, and a monitor (not shown in the figure). Moreover, in FIG. 1, an X-axis, a Y-axis and a Z-axis are set respectively in the lateral, longitudinal and vertical directions of the system main body 111. Further, in FIGS. 2A, 2B and 3, an X-axis, a Y-axis and a Z-axis are set respectively in the longitudinal, lateral and vertical directions of the optical fiber fixing system 105 (125). The X-axis, Y-axis and Z-axis are perpendicular to one another.
The optical fiber fixing systems 105, 105 are disposed respectively along the X-axis at the equal distances from the butting section 107. The optical fiber fixing systems 105, 105 fix the optical fibers 103, 103 respectively. The discharge electrodes 109, 109 are disposed respectively along the Y-axis at the equal distances from the butting section 107. The discharge electrodes 109, 109 are used for fusing the end surfaces of the optical fibers 103, 103. The windshield cover 113 is configured such that it may be opened and shut around the hinge portion 114 attached to the +Y side portion of the system main body 111, and protects the butting section 107. The monitor is disposed on the side of the system main body 111.
Parenthetically, an optical fiber butting system includes the components of the optical fiber fusion-splicing system 101 except for the discharge electrodes 109, 109, and is a system for butting the optical fibers 103, 103 to align them with each other.
The optical fiber fixing system 105 is, as shown in FIG. 2A, includes a clamp base 115 and a clamp member 119. FIG. 2A shows the optical fiber fixing system 105, which has been shown on the −X side in FIG. 1. Further, the optical fiber fixing system 105 shown on the +X side in FIG. 1 has the same configuration as that in FIG. 2A. The clamp base 115 has, on its top surface, a V-groove 117 for mounting the optical fiber 103 and is attached to the system main body 111. The depth of the V-groove 117 is designed so that a ridgeline of the optical fiber 103 may be located within the V-groove 117. The clamp member 119 has a protrusion 123 on the bottom surface of its +X side end portion. Slopes 121, 121 are formed on both sides of the protrusion 123 and are fitted into the V-groove 117. When the optical fiber 103 is fixed using the optical fiber fixing system 105, the optical fiber 103 is arranged along the V-groove 117 and then the optical fiber 103 is depressed against the V-groove 117 using the clamp member 119. The clamp member 119 is usually made of a resin so as not to damage the optical fiber 103.
However, the optical fiber fixing system 105 has the following two problems. The first one is that the clamp member 119 has a poor anti-abrasion characteristic since the clamp member 119 is made of a resin. The second one is that the optical fiber 103 is liable to be off the bottom surface of the protrusion 123 as shown in FIG. 2B since the protrusion 123 of the clamp member 119 is not configured so as to guide the optical fiber 103 to the bottom portion of the V-groove 117.
Alternatively to the optical fiber fixing system 105, an optical fiber fixing system 125 has been developed. The optical fiber fixing system 125 includes, as shown in FIG. 3, a clamp base 127 and a clamp member 133. The clamp base 127 has, on its top surface, a first V-groove 129 and a second V-groove 131 for mounting an optical fiber 103, and is attached to a system main body 111. The depth of the first V-groove 129 is designed so that a ridgeline of the optical fiber 103 may be located above the first V-groove 129. The depth of the second V-groove 131 is designed so that the ridgeline of the optical fiber 103 may be located within the second V-groove 131. A bottom surface 135 of the clamp member 133 has the shape of a plane. When the optical fiber 103 is fixed using the optical fiber fixing system 125, the optical fiber 103 is mounted in along the first V-groove 129 and the second V-groove 131, and then the ridgeline of the optical fiber 103, which projects over the first V-groove, is depressed against the first V-groove 129 using the clamp member 133. At that time, the second V-groove 131 restricts the movement of the optical fiber 103 in the direction of Y-axis. The bottom surface 135 of the clamp member 133 goes down maintaining to be parallel to the X-Y plane and contacts the ridgeline of the optical fiber 103. Usually, the clamp member 133 is made of a ceramic in order to reduce friction with the optical fiber 103.
However, the optical fiber fixing system 125 has the following two problems. The first one is that it is difficult to set easily the optical fiber 103 on the clamp base 127 since the first V-groove is formed to be longer than the second V-groove along the axial direction of the optical fiber 103. The second one is that the clamp member 133 is likely to become expensive and is liable to damage the surface of the optical fiber 103 since the clamp member 133 is made of a ceramic.